<!DOCTYPE html>
<html>
<head>
<title>Service Worker GlobalScope onerror event</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
</head>
<body>
<canvas id=canvas></canvas>
<script>
var registration;

async function registerServiceWorker()
{
    const registration = await navigator.serviceWorker.register("message-event-ports-worker.js", { scope : "." });
    let activeWorker = registration.active;
    if (activeWorker)
        return registration;
    activeWorker = registration.installing;
    return new Promise(resolve => {
        activeWorker.addEventListener('statechange', () => {
            if (activeWorker.state === "activated")
                resolve(registration);
        });
    });
}

promise_test(async (test) => {
    registration = await registerServiceWorker();

    registration.active.postMessage("test");
    let result = await new Promise(resolve => navigator.serviceWorker.onmessage = e => resolve(e.data));
    assert_equals(result, "same ports array", "empty array");

    const channel = new MessageChannel();;
    const port = channel.port1;
    registration.active.postMessage({ port }, [port]);
    result = await new Promise(resolve => navigator.serviceWorker.onmessage = e => resolve(e.data));
    assert_equals(result, "same ports array", "not empty array");
}, "Verify MessageEvent.ports getter returns the same object");
</script>
</body>
</html>
